bbPress

Description

Have you ever been frustrated with forum or bulletin board software that was slow, bloated and always got your server hacked? bbPress is focused on ease of integration, ease of use, web standards, and speed.

We’re keeping things as small and light as possible while still allowing for great add-on features through WordPress’s extensive plugin system. What does all that mean? bbPress is lean, mean, and ready to take on any job you throw at it.

Screenshots

Installation

From your WordPress dashboard

Visit ‘Plugins > Add New’

Search for ‘bbPress’

Activate bbPress from your Plugins page. (You’ll be greeted with a Welcome page.)

There never was, and there never will be any kind of anti-spam plugin made for BBpress. You're better off switching to a non-WordPress-based forum software. There's nothing that WordPress can do about spam unless you pay monthly for it. Sad how WordPress used to be a free, open-source kind of community and now all it is, is fake-free plugins.
edit: So it's not abandonware, I've changed the title.
edit2: WP-Spamshield what people are looking for, not Akismet.